Metadata Validator element

The goal of the Validator element is to ensure that the user provides the necessary, properly formatted information to complete an operation successfully.

The validator can only be used in combination with other fields:

• Metadata Checkbox field
• Metadata Input field
• Metadata Select field
• Metadata Suggestbox field
• Metadata TextArea field

Validator element attributes

Attribute	Description	Required
type	The validator type. See the list of available validators below.	true
parameter	An optional value passed to the validator. For length validators (maxlen, minlen), specifies the limit. For comparison validators (lt, gt, min, max), specifies the threshold. For regexp, specifies the regular expression pattern. For plugin, not used.	false

Available validators:

name	Description
req	Required value.
alpha	Alphabetic value.
alphanum	Alphanumeric value.
dec	Decimal value.
num	Numeric value.
email	Email value.
url	URL value.
maxlen	Maximum allowed length.
minlen	Minimum required length.
lt	Less than.
gt	Greater than.
min	Minimum value.
max	Maximum value.
regexp	Regular expression.
plugin	Create your own form validator. More information at Creating your own Form Validator plugin.

• Parent:

Basic example

• Value required: “req”.
• The value must be a decimal: “dec”.
• The maximum length of the decimal value is six digits: “maxlen”.

<input label="Decimal value" name="okp:consulting.decimal">
    <validator type="dec" />
    <validator type="req" />
    <validator type="maxlen" parameter="6" />
</input>

Regular expression

You can use a regular expression if you want a validation that is not included among these predefined validators. For example, imagine you want to restrict an input to lowercase ASCII characters:

<input label="Lowercase value" name="regExp">
    <validator type="regexp" parameter="[a-z]+" />
</input>